Nov 16, 2016 Pregnancy

Pregnancy happens when a female’s egg is fertilized with the sperm from a male Fertilization occurs in the fallopian tubes

Only one sperm will fertilize the egg (unless there are twins)

- The new egg cell once it has been fertilized by the sperm Zygote - The new egg cell once it has been fertilized by the sperm - Travels to the uterus, and begins mitosis

Blastocyst - What the zygote is called once it reaches the uterus - Inner cells form the embryo - Outer cells form the placenta

Embryo needs to attach itself to the thickened lining of the uterus, which is called implantation Happens 6-10 days after the egg is fertilized This is technically when pregnancy begins Hormones tell the body to keep the uterine lining, which will be used for nutrition for the embryo

During the first week of pregnancy, all of the cells are similar to each other In the second week, the cells begin to specialize and can be arranged into 3 distinct layers:

1. Ectoderm – the outer layer that forms the skin & nervous system 2 1. Ectoderm – the outer layer that forms the skin & nervous system 2. Mesoderm – the middle layer that forms the kidneys, skeleton, muscles and blood vessels 3. Endoderm – innermost layer that forms the lungs and digestive tract

- Supplies nutrients and oxygen to the developing embryo Placenta - Supplies nutrients and oxygen to the developing embryo Removes the wastes that are created by the embryo Is an organ that the mother grows and will deliver at birth

- Attaches the embryo to the placenta Umbilical Cord - Attaches the embryo to the placenta - Is cut at birth - It shrinks and becomes the belly button (navel) (innie and outie!)

The embryo grows really fast A tube-like heart starts beating at approximately 3 weeks By the end of the 4th week the embryo is 500 times bigger than its original size

It takes 38 weeks (9 months) for the baby to develop Pregnancy is divided into 3 trimesters, each of which are approximately 3 months long

1st Trimester – Weeks 1-12  

2nd Trimester – Weeks 12-24

3rd Trimester – Weeks 24-38

BIRTH Occurs approximately 9 months after pregnancy begins. Survival Rates: 20-35% born at 23 weeks 50-70% born at 24 to 25 weeks more than 90% born at 26 to 27 weeks,

Labour is triggered by hormonal changes. The cervix dilates to allow for the baby to get through it.

Contractions by the uterus force the baby into the birth canal and out of the body.

The baby will get into position during the last few weeks of pregnancy, with its head down and dropping. The baby is usually delivered head first.

The placenta is delivered after the baby The placenta is delivered after the baby. It is very important to get ALL of the placenta.

Breastfeeding Hormone changes during pregnancy and birth, allow the mother to develop milk in her breasts. If a baby is not breast-fed, a baby must be bottle-fed in order to thrive.

Infancy From birth to age 2 years The baby learns to feed. Its main concern is to find the nipple. It will turn its head and “root” to find the nipple.

Childhood Age 2 – puberty Large amount of physical growth Development of motor, memory and language skills

Puberty Hormones stimulate sexual maturity Growth ends at the end of puberty and adolescence

Aging Aging starts in the late 20s. Life expectancy:

Check out this beautiful lady!